I would like to get to know this gun a bit better and any help is greatly appreciated! Sometimes you have to fire a round twice in order to get it to fire it doesnt look like the pin is striking the primer as hard as it should. There are several possibilities/contributing factors: 1) The firing pin is badly worn.
Solution: replace. 2) The spring is indeed weak. Solution: replace. 3) The bolt body is clogged up with fossilized grease. Solution: dismantle, clean, reassemble. 4) Severely excessive headspace may be a contributing factor, but not the sole cause, although someone will probably tell you so.